Inliners International Forums General Discussion Blown and Injected Fabricating Turbo header

I'm thinking of fabricating my own turbo header. Exhaust flange sets are available in 3/8" and 1/2". Would 3/8" be better because it's closer to the thickness of the Clifford intake manifold flanges?

Yes, have them close to the same thickness.

MBHD

My inclination from my experience would be to use the 1/2" flanges and just machine the flange where it needs to be the same as the intake. By using the 1/2" you get less warpage and you have more meat you can machine off when you are flattening the flange. Ultimately I think you'll end up with less exhaust leak problems.


M5

I like that idea M5. I'm going to go ahead and order the 1/2" flange.

So I'm thinking of using a mandrel bent tubing kit with a T4 flange and wastegate flange. Any tips or suggestions on the design?
Thanks

What engine are you building it for.

chevy 250.

Some ideas.
http://cgi.ebay.com/ebaymotors/BMW-E30-A...sQ5fAccessories

http://cgi.ebay.com/ebaymotors/SPA-Turbo...sQ5fAccessories

http://cgi.ebay.com/ebaymotors/BMW-98-99...sQ5fAccessories

http://cgi.ebay.com/ebaymotors/92-98-BMW...sQ5fAccessories

You can run just a log type manifold & will work fine,plus it's easier to fab up.

MBHD

I've been thinking of going the header route as well but if I do it will be made out of 321 stainless. I've been through several headers before on other projects that were made out of 304 and they just don't stand up to the heat cycles, and once they crack they are done, you will be constantly welding them. For my time and money I'm really leaning towards just buyin the SPA T4 turbo manifold and calling it done. You won't be able to build a decent tube header for what it costs to get the manifold. From just thinking about it at this point it seems to me that there are lots of other places to make the system more efficient prior to building a tube headsr. JMO.

M5

For an actual race car a header has some advantages.
For a street-driven vehicle, the increase in underhood temp is very annoying - the total surface area of a header is much larger than any casting or fabricated weld-ell. It reduces gas temp reaching the turbine inlet somewhat, so the higher gas speed doesn't work as well as it looks. it makes a cold air inlet (outside the bay) more critical. It's a bit noisier. Obviously, it's more leak and crack-prone just due to the number of joints and even a small leak kills boost.
Bell has some useful comments on dump and bypass location on an L engine and IIRC (haven't read it in 10 years) the end isn't the best.

Good call on the underhood temps and longevity guys. Didn't really think that through I guess. I've just heard that the SPA manifold isn't that great. Is there anything else out there?

The SPA manifold is a good part. I like to have it machined to accept a T4 turbo flange. They are made for a T3 flange. There are very few T3 turbo choices that use a remote wastegate. And the T3 cannot move as much exhaust volume.
The T4 can normally be had with remote WG and come with a much wider array of exh housing sizes.

SPA will not ( as of now) machine the manifolds with a T4 flange. I used to sell them. They're casting is setup for a T3 flange. The ones sold on ebay with a T4 flange are welded up T3 and remachined to a T4.

What vehicle is the turbo manifold for? That will let us know if the SPA manifold will fit your app.

The SPA manifolds only real flaw, mainly the wastegate location is not near the center dump .Not a big deal,it works fine from what I have heard,so don't let that make you not purchase one. It's a really nice manifold!
As far as I know,, there is no other manifolds made for our engines.
Other than the wastegate location,it is a well built manifold & the design is much better than a log type manifold.

I have one & plan on using it someday on my old 250 longblock.
Looking to get approx 400 hp to the wheels @ least .

I remember a guy in Brazil making 860 HP w/a SPA manifold on 250 CI engine.
That is a lot of HP, a tubular well designed manifolds will make the most HP,,,but,, you need to ask yourself,are you looking for every last bit of HP available?

For now, I am looking for easier simple install on a turbo set-up & the SPA manifold is perfect for my needs. Heck if tuned correct my old 250 could make approx 625 HP @ the crank ,not for long, but its possible w/the supporting components I have.

The SPA manifold is a tight fit on my 69 Camaro,but it is doable.
So basically it will fit 67-69 Camaros, 68-73 ,74? Novas, Omegas,Skylarks,Pontiac ?? basically the GM versions of those Novas 68-73 -74?.

They will probably fit newer years also,but I have not seen them in any.

The stock restrictive Syclone/Typhoom exhaust manifolds have made 750+ HP to the wheels.
Here is a post w/some pics of the manifolds.
http://www.syty.net/forums/showthread.php?t=79209

One last thing,,321 stainless tubing is very,very pricey$$$$$
It has titanium in it also.
MBHD

The vehicle I'm going to turbo is a 1967 C10. It's in my signature link. I was mainly thinking of a header to keep the costs down and still have money left over to have it ceramic coated.

You could always use Toms Langdons exhaust manifolds also.

http://stoveboltengineco.com/index.php/c...product=1395980

I was going to use these for my turbo app,but found the SPA manifold & plan on using that.

MBHD